Remember to copy both boot and image files before rebooting the stack.( If applicable)
Since firmware always gets uploaded on the non-active partition you need to run the
following command for each switch.

DWS/DXS-32xx# boot system unit 8 image-2

This is an example considering that this is 8th unit of the stack and non active
image is 2.
You need to run this command for every switch of the stack.